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Topic: Jacking Rings. (Read 2984 times)

G'day, If you are like me and have read most posts on the forum then you've probably heard the term, "jacking rings". Also if you are like me and like to go bush a bit and tend to overload your moke then this is an easy and recommended modification to do. Firstly i have to thank Terry for telling me how to do it. He probably learned tha hard way and we get the benefit of it. When we went on our power line run he was mortified at what i carried with me and also informed me thet the Ratster was resting on the rear bump stops. Even though it was raised with hilo's. Rear bump stops i hear you ask? I thought the same thing theres no rubber bump stops back there but there is a bump stop and I'll show you. First the rubber donut when its under load, it does more than just compress. It tries to turn itself inside out and to stop this, there is a raised bump in the subframe that doesn't allow the donut to do it therefore it bottoms out or rests on the bump stop.

Heres a pic of the bump stop. the inside of the concave part of the donut hits that mound.

The next thing you have to do is to remove most of that mound. A 4" angle grinder is the only way and its not the neatest but its not seen.

Now you have to make a jacking ring. These fit around the base of the Donut and give clearence for the donut to compress further with out bottoming out. I made mine out of a strip of steel 25mm wide was cut from a gas bottle as it was sort of heading in the right direction.( roundish) The gas bottle was empty by the way Heres how i made them.

The strips were then folded around an old hub to get the shape

They were then welded and cleaned up. The finished product

This is what they look like fitted to the donut

Then the donut and hilo assembly was refitted.

What this does is raise the rear suspension a bit and adjusted to the required height via the hilos. But most important is with weight or rough terrain (or both) the donuts are able to do their job, even nearly turn inside out if they had to with out bottoming on the bump stop. Giving a less rigid ride.

Smoken has pretty much covered the basics, but I am not sure that people should be cutting up LPG cylinders to get the metal, but otherwise the advice is pretty much correct from Smoken and Moe.

A couple of things to add is the guy who originally built the Gryphon, as the Griffin, Robin Booth first bought the idea into the Clubs about 20 years or so ago and I learnt italong the way so i can only take credit for passing on. The ones being sold by the club are no longer available and I did manage to break the last two I bought so I have been making my own since. Peter L. has a set of mine in The Stealth but they are big and heavy duty ones so you do need the adjustable suspension to make it sit right.

And the ratio on the rear is 7:1 so 1mm on the jacking ring is 7mm in ride height. The ones smoken made were 25mm, or I suggested 20mm, but you do lose a lot of that as it slips over the donut and it will become a snug fit once bedded in so you can expect around 5-10 mm increase at the end of the day. The jacking ring isn't the only method to do what is required but it is the easiest that does requiring machines.

Smoken has pretty much covered the basics, but I am not sure that people should be cutting up LPG cylinders to get the metal, but otherwise the advice is pretty much correct from Smoken and Moe.

Terry

That had occurred to me too Terry. Smoken probably knew the cylinder was well and truly empty (I hope ) but it's a dangerous trick for some of the less experienced members to try. One way you can be 100% confident it is safe is to take the valve out of the top and fill it with water, letting it overflow out the top. Then you can tip the water out and cut away with 100% confidence that there can be no gas left. We used to use the same method for cutting up old fuel containers (another operation that you can easily find numerous woorkcover case studies on) to remove the residual explosive fumes.

Little details like the fact that LPG is actually heavier than air traps the unwary. They let the gas out of the top valve and assume it is empty. In actual fact, all the pressurised gas is gone, but there is a residual pool of unpressurised gas left in the cylinder. Filling it with water to overflowing point forces all of the gas out.

Newie

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1966 Moke - "The Gnome" Current work in progress1979 Californian - Going, but a long long long way from roadworthy.Plus a couple of other garden gnomes for parts

I'm a genius in disguise............It's a bloody good disguise-no one ever suspects a thing

The extra washers Bnicho describes are probably the ones from under the bolts that hold on the rocker cover and has two issues. First is that they only change the ride height and not the amount of suspension travel so the Moke might look better but will still be riding on the bumpstops or near to them. Also putting too many washers on have been known to crack the end of the trumpet because there is not enough shaft from the ball inside the thick area of the trumpet.

The adjustable suspension in the rear isn't really the issue that (watto?) is suggesting but the rear arm extension that is used by most Mini shops. The extension used is commonly from a Hydralastic Mini and although it works in a Mini they do bend when you use them in a Moke, the main reason is the extra leverage of the longer trailing arm. So a normal adjustable suspension with a heavy duty extension is fine.

As for the use of Springs there are numerous ones available these days and they are getting better but they seems to suffer a problem of being too stiff and hard for the front of a mini so in the rear of a Moke you may as well just stick a block of wood in there. This may change with a heavily loaded Moke but for the time being a decent donut with the mods mentioned in this thread are usually a simple, cheap and effective solution.